Adiscus pubiventris Medvedev, 2008

Duan, Wen-Yuan & Zhou, Hong-Zhang, 2022, Revision of the genus Adiscus Gistel, 1857 (Coleoptera: Chrysomelidae, Cryptocephalinae) from mainland China, Zootaxa 5096 (1), pp. 1-80 : 63-64

Adiscus pubiventris Medvedev, 2008

(Figs 26-1; 26-2)

Adiscus pubiventris Medvedev, 2008: 202 (type locality: Vietnam and Laos; type deposited: LM).

Material examined. CHINA: Jiangxi Province [New record]: 1 female, Mt. Jiulian [Jiulianshan], 8. VI. 1975, coll. Youwei Zhang ( IZ-CAS) ; Guangxi Province: 3 males, 5 females, Lingui, Wantian , 1. VII. 1963, coll. Shuyong Wang ( IZ-CAS) ; 1 female, Lingui, Wantian , 17. VI. 1963, coll. Shuyong Wang ( IZ-CAS) ; 1 female, Longsheng, Sanmen , 26. VI. 1963, coll. Chunguang Wang ( IZ-CAS) ; 1 male, Jinxiu, Mt. Lianhua [Lianhuashan], 20. VI. 1999, coll. Wenzhu Li ( IZ-CAS) ; Guizhou Province: 2 females, Shixian , 23. VII. 1988, coll. Shuyong Wang ( IZ-CAS) ; 1 female, Mt. Foding [Fodingshan], 23. VII. 1988, coll. Xingke Yang ( IZ-CAS) .

Redescription. Measurements. Males. BL = 4.21–4.56 mm, BW = 3.24–3.65 mm, HL = 1.41 mm, HW = 1.26 mm, PL = 1.24 mm, PW = 2.86 mm, PA = 90°, EL = 3.37 mm, EA = 110°, AL = 1.43 mm, AW = 0.44 mm.

Females. BL = 4.51–4.96 mm, BW = 3.48–3.85 mm, HL = 1.53 mm, HW = 1.36 mm, PL = 1.34 mm, PW = 3.09 mm, PA = 90°, EL = 3.65 mm, EA = 110°, SL = 0.65 mm.

Body (Figs. 26-1A; 26-2A) short and ovate, dorsum mostly reddish fulvous. Head reddish brown; mandibles reddish brown, apex black. Apical segments of antennae more or less darkened. Pronotum fulvous, basal margin black. Legs and venter yellowish brown.

Head shiny, frons with fine and dense punctures, mixed with minute punctures. Clypeus with straight anterior margin, densely granulose and sparsely punctate. Antennae long, reaching area behind elytral humeri; scape thick, clubbed, pedicel spherical, antennomeres 3 and 4 tinny, 4 longer than 3; 5–10 somewhat broadened and flattened, the last segment pointed apically.

Pronotum (Figs. 26-1A; 26-2A) convex, smooth and shiny, base much broader than apex, basal width about 2.3 times of pronotal length. Anterior margin nearly straight. Posterior margin slightly sinuate with fine serration, and produced into right-angle of about 90° at middle. Disc evenly convex, impunctate.

Elytra (Figs. 26-1A; 26-2A) wide to long, humeri somewhat prominent, glabrous, widest slightly behind humerus, feebly rounded at sides and apex. Disc distinctly punctate, with 11 regular striae, intervals with scattered weak and minute punctures. Epipleural lobe (Fig. 26-2B) large, lateral margins distinctly expanded ventrally and with triangular lobe at basal 1/4 of elytron, with both lobe sides forming angle of 110°, epipleura invisible in lateral view.

Venter clothed with sparse short pubescence and dense fine punctures. Prosternum (Fig. 26-2C) trapezoidal, anterior margin concave; lateral ridge sharp, straight in lateral view; anterior of central ridge elevated, with rounded apex; posterior margin protruding backward. Mesoventrite broad, about 2.5 times as wide as long, lateral margin slightly protruding. The first segment of fore and mid tarsi broadened. The first abdominal ventrite between hind coxae with long and curly hairs. Pygidium with dense coarse punctures.

Aedeagus. (Figs. 26-1D–F; 26-2D–F) Median lobe elongate, about 3.1 times as long as wide, nearly parallelsided. Apex of median lobe slightly narrower than middle, apex narrowly rounded, strongly curved in lateral view; with setae on each side of apex and upper region of ventral side, punctate on ventral side of distal part. Median orifice with median sclerite bending inwards above surface. Inner sac longer than wide, a paired structure, connected at base with duct. Tegmen Y-shaped, weakly sclerotized, almost translucent.

Female. Body more robust than male, apical hollow in ventrite 5 deep and round, without brush of setae on first ventrite. Spermatheca (Figs. 26-1C; 26-2G) falcate, 60°-angled bending halfway, slightly acute at apex, strongly dilated at base 1/3, then narrower downward; duct weakly sclerotized, irregularly coiling 4–6 times. Rectal sclerites (Fig. 26-1G) moderately sclerotized, not connected between two clubbed sclerites on ventral side.

Distribution. China (Jiangxi, Guangxi, Guizhou); Vietnam, Laos.

Diadnosis. Easily distinguished by the first abdominal ventrite of male with brush of erect hairs.